The semiconductor integrated circuit industry has experienced rapid growth in the past several decades. Technological advances in semiconductor materials and design have produced increasingly smaller and more complex circuits. These material and design advances have been made possible as the technologies related to processing and manufacturing have also undergone technical advances. In the course of semiconductor evolution, the number of interconnected devices per unit of area has increased as the size of the smallest component that can be reliably created has decreased.
Many of the technological advances in semiconductors have occurred in the field of memory devices. Resistive random access memory (RRAM) is a nonvolatile memory type that is one possible candidate for future advancement in memory technology. Generally, RRAM cells typically use a dielectric material, which although normally insulating can be made to conduct through a filament or conduction path formed after application of a specific voltage. Once the filament is formed, it may be set (i.e., re-formed, resulting in a lower resistance across the RRAM cell) or reset (i.e., broken, resulting in a high resistance across the RRAM cell) by appropriately applied voltages. The low and high resistance states can be utilized to indicate a digital signal of “1” or “0” depending upon the resistance state, and thereby provide a nonvolatile memory cell that can store a bit.
Embedded memory products, like many other semiconductor products, face fabrication time and cost pressures. The ability to fabricate RRAM cells using fewer and/or simpler process steps is highly desirable. RRAM cells that may be formed using, at least in part, some of the same process steps that simultaneously form desired structures in the logic region of a device are also highly desirable. Accordingly, it would be desirable to provide an improved RRAM cell structure and fabrication process.
The various features disclosed in the drawings briefly described above will become more apparent to one of skill in the art upon reading the detailed description below. Where features depicted in the various figures are common between two or more figures, the same identifying numerals have been used for clarity of description.